Abstract

The purpose of this study was to investigate muscle synergies (MS) during upper limb cycling motion across power levels (20, 40, 60, 80, 100, and 120 watts). The MS hypothesis is important to the understanding of modular control for human movements. In this study, we explore its importance in execution of phasic movements at various power levels. Electromyographic (EMG) signals were recorded from 7 upper limb muscles during cycling for 30s on a hand-cycle ergometer. A Non-Negative Matrix factorization (NNMF) algorithm was used to extract MS. Cosine similarity was used to compare the MS and cross-correlation was used to compare activation coefficients. We found that the number and structure of synergies were consistent across power levels while admitting modulation in their activation coefficients. A total of three shared MS explaining ≥95% of the variance accounted for (VAF) represented push and pull mechanism during cyclic motion.

摘要

本研究的目的是研究上肢骑自行车运动期间跨功率水平（20、40、60、80、100 和 120 瓦）的肌肉协同作用 (MS)。MS 假设对于理解人体运动的模块化控制很重要。在这项研究中，我们探讨了它在执行不同功率级别的相位运动中的重要性。在手动自行车测力计上骑自行车 30 秒期间，从 7 块上肢肌肉中记录了肌电图 (EMG) 信号。非负矩阵分解 (NNMF) 算法用于提取 MS。余弦相似度用于比较 MS，互相关用于比较激活系数。我们发现协同作用的数量和结构在不同功率水平上是一致的，同时承认其激活系数的调制。